Ultrastructural effects of cadmium on the rat epididymis.

The short-term effect of a subcutaneous injection of 3 mumol of cadmium chloride/100 g body weight were examined 90 min later in male rats. The main target of cadmium, as shown by electron microscopy, was the endothelial lining of capillaries of the caput epididymidis. Intercellular junctions between endothelial cells were disorganized, ranging from slight separation between cytoplasmic leaflets to wide gaps which communicated freely with the pericapillary tissue. Disruption of platelets and intravascular clotting followed these early endothelial lesions, and clotting was found in venules as an extension of clotting from the capillaries. Pre-treatment with zinc (300 mumol zinc chloride/100 g body weight) prevented all of the lesions described above.